Giant coronary artery aneurysm associated with Kawasaki disease showing progressive dilation over 30 years.

A 33-year-old pregnant woman with a history of a giant coronary artery aneurysm (CAA) of the right coronary artery owing to Kawasaki disease (KD) was referred to our hospital for the management of pregnancy and delivery. The CAA was detected when she was 10 months old on the 24th day from the onset of KD and showed transient regression followed by progressive dilation and reached a size of 25 mm when she was 30 years old. The baby was delivered at 38 weeks of gestational age. Resection of the CAA and coronary artery bypass grafting were performed 5 months after the delivery. Pathological results suggest that progressive dilation of the CAA was owing to a reduction in elastic recoiling force caused by partial destruction of the internal elastic lamina and degenerated tunica media against an increase in blood pressure that accompanied the growth of the patient. The pathophysiology of CAAs with atypical clinical course may be different from that of typical CAAs owing to KD. <Learning objective: Kawasaki disease (KD) causes varying sizes of coronary artery aneurysms (CAAs). In this case, rare progressive dilation of the CAA owing to KD was observed in the remote phase. We revealed different pathological features of rare CAAs from those of a typical one; progressive dilation of the CAA could be owing to the reduction of recoiling force. Planned surgical treatment of a CAA showing continuous dilation should be a reasonable option for avoiding emergent CAA rupture.>.